Hot-cathode tube



Apr. 3, '1923.

J. SLEPIAN HOT CATHODE TUBE Filed Apr. 18, 1919 INVENTOR Joseph Slap/an. BY

ATTORNEY WITNESSES:

. 30 large amount of heat Patented Apr. 3, 1923.

UNITED STATES PATENT oreica.

JOSEPH SLEPIAN, or WILKINSIBURG, IIENNSYLVANIIA, ASSIGNOR 'ro -WESTII\TGHQUSE ELECTRIC & MANUFACTURING COMPANY, A ooRPoRA'rroN or PENNSYLVANIA.

How-cantons TUBE.

Application filed April 18,

To all whom it may concem Beit known" that I JOSEPH SLEPIAN, a: citizen of the United S tates, and a resident of Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Hot-Cathode Tubes, of which the following is a specifieation.

My invention relates to hot-cathode ap- 1 paratus, such as is used for rectification and in detector bulb work and it has for its object to provide apparatus of the character designated that shall embody means for pro viding a strong and effective electron emission. j

The single figure of the accompanying drawing is a diagrammatic View of an electron tube, together with associated supply and auxiliary circuits, illustrating one application of my invention.

In the construction and operation of electron tubes, it has been usual to employ incandescent filaments as electron thesev filaments being maintained at incandes cence by the passage of heating current therethrough. The use of a filament of sufficient size and large electron streams required in certain forms of apparatus engenders a relatively that must be dissipated and, furthermore, the filament is subect to rapid deterioration because of the high temperature at which it must be run, thus limiting the useful life of the apparatus. 1

I find that a relatively filament may be operated at moderate temperatures to produce a small number of electrons andthese electrons may be caused to make impact upon an adjacent electrode with high velocity by subjecting them to the "influence of a high-voltageelectrostatic field. As a result, there is produced a profuse emission of electrons from the adjacent electrode by the joint action of reflection and of secondary emission, it being well known that the impact of a high-velocity electron upon another body may set free a large number of: low-velocity electrons therefrom.

The. adjacent electrode, .which is thus caused to be the seat of a profuse electron,

, emission, may now be employed as a cathode in an auxiliary circuit, and a relatively large amount of current may be offered passage and this sources,

temperature to produce the small incandescing' 'poles adjacent to the electrodes 6, 7 and 8,

1919. Serial lifp. 291,158.

If desired, the above process may be repeated, and the electrons set free from the adjacent electrode be caused to make impact upon still anotherelectrode, setting free a still larger number of electrons therefrom,

process may be continued indefinitely.

A convenient method of manipulating the electron streams, in apparatus of thistype,

is by means of magnetlc fields.

Referring to the drawin for a more de-' tailed understanding of my invention, I show a tube at 5 which may either be highly exhausted or filled to a greater or less degree with a gas, such as argon, which offers an elastic impact, as is well known in the art. The tube '5 is provided With a filamentary I electrode 6 and with a plate electrode 7 substantially in line therewith.

A plate electrode8 is disposed'opposite the electrodes 6 and. 7, and a plate electrode 9 is disposed in angular position at the side of the electrode 7.

eating current for the filament 6- is provided from a source 10, and the electrode 8 is maintained positive with respect to the electrode 6 by current from a source 11. The electrode 7 is maintained positive with respect to the electrode 6 by current from asource 12 and a unidirectional load-current device 13 isconnected in circuit with the electrodes 7 and 9 through an alternatingcurrent source 14.

A magnet15 is disposed with one of its as shown.

Having thus described a combination of devices embodying my invention, the operation thereof is as follows. At the outset, the filament 6 is raised to ineandeseenceand arelatively small number of electrons caused to be emitted therefrom. These electrons are drawn toward the electrode 8 and arela- 'tively high velocity is imparted thereto by current from the source 11. Before reaching the plate, however; the electrons are di rected 'into a eycloidal path, bythe action of the magnet 15, to impinge upon the electrode 7 at an extremely high velocity. 'A certam number of the 'electrons, (upon reaching theelectrode 7, return to the cathode 16 through the current source 12, although, at the ment of impact, they set free a relatively large number of low-velocity electrons at the surface of the plate 7.-

Certain other electrons, upon reaching the plate 7, set free other electrons and are then reflected so as to hit the plate 9. The plate 7 is thus caused to. be a seat of profuse lowvelocity electron emission and operates as a cathode in the circuit including the electrodes 7 and 9, the load 13 and the alternating-current source 14;. 1

Thus, a relatively large electron stream may be maintained between the electrodes 7 and 9, for the rectification of large currents, with the operation of but a small filament 6, this filament being operative at moderate temperatures so as to be long-lived.

As previously set forth, this action may be repeated to any desired degree, the large electron emission from the electrode 7 being suitably directed, if desired, so as to make impact upon another electrode, a high velocity being imparted thereto by a suitable impelling electromotive force, and a suitable magnet or other means being employed for directing the electron stream.

While I have illustrated my invention for.

use in a rectifier, it is obvious that it may be employed to equal advantage in any other form of electron tube Where profuse emission is desired, as in detector and amplifier work.

While I have shown my.invention in its a preferred form,'it is susceptible of still other modifications and changes without departing from'the spirit thereof and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or are specifically. set forth in the appended claims.

I claim as my invention:

1. In a rectifying device, the combination with means for producing an electron stream, of a circuit including two spaced electrodes, an alternating-current source and a load, and means for deflecting said electron stream upon one of Said electrodes whereby it functions as a cathode by secondary emission and by reflection and permits the rectification of current from said source.

2. In a rectifying device, the combination with means for producing an electron stream, of a circuit including two spaced electrodes, an alternating-current source and a load, and a magnet for deflecting said electron stream upon one of said electrodes whereby it functions as a cathode by secondary emission and by reflection and permits the rectification of current from said source. 3..The method of initiating rectification in a circuit including two Spaced electrodes,

an alternating-current source and a load,

which comprises bombarding only one of said electrodes with an electron stream 1n such manner as to cause an electron emission to be initiated thereat by reflection and by secondary emission.

4. The method of initiating rectification in a relatively low-voltage circuit including a pair of spaced electrodes, an alternatingcurrent source and a load which comprises bOmbarding only one of said electrodes with a stream of relatively few, high-velocity electrons and producing therefrom an emission of a relatively large number of lowvelocity electrons by reflection and secondary emission.

5. In an electron tube, the combination with means for producing an electron stream embodying relatively few high-velocity electrons, of an electrode in the path of said stream, whereby a relatively large number of electrons are produced by reflection and secondary emission, and means including an anode and an electric circuit for utilizing said last-mentioned electron stream, said means being located substantially out of the path of said first-mentioned stream.

(3. In an electron tubefthe combination with an incandescing cathode, of means comprising an electrostatic field for directing and imparting high velocity to the electrons emission, of a solid body disposed adjacent thereto, and magnetic means for deflecting said primary emission upon said solid body in such manner as to produce a secondary electron emission in a direction suitable for carrying said secondary emission out of the pathof said primary emission.

8. In apparatus for producing secondary electron emission. the combination with means for producing a primary electron emission, of means for imparting highvelocity to said primary emission. a solid body disposed adjacent thereto, and magnetic means for deflecting said primary emission upon said solid body in such manner as to produce a secondary electron emission in a direction suitable for carrying said secondary emission out of the path of said primary emission.

9. In apparatus for producing a profuse electron emission, the combination with means for producing a relatively small electron emission, of electrostatic means for imparting high velocity thereto, a solid body. and magnetic means for deflecting said small electron emission upon said solid body in such manner as to produce a. secondary electron emission in a direction suitable for carrying said secondary emission out of the path of said primary emission.

10. In apparatus for producing secondary electron emission, the combination with means for producing a primary electron emission, of a plate disposed in such manner as to receive said primary electron emission at an acute angle to the surface thereof, said plate being adapted to emit secondary electrons, a second plate disposed so as to selectively receive the electrons emitted by said first-mentioned plate, and an electric circuit associated with said second plate.

11. In apparatus for producing secondary electron emission, the combination of means for producing a primary-electron emission, of an electrode for producing a secondary electron emission upon being bombarded With said primary electron emission, said electrode being so disposed that the paths of said primary electron emission and said secondary electron emission are substantially different, and means includin an electriccircuit for utilizing said secondary electron emisslon.

12. A rectifying device comprising an electrode, means for producing an unobstructed flow of primary electrons impinging upon said electrode whereby a secondary electron stream is produced, and means including an anode and an electric circuit for utilizing said" last mentioned electron stream.

13. A rectifying device comprising anelectrode, means for producing an unobstructed flow of primary electrons imping- 'ing upon said electrode whereby a secondary electron stream is produced, and an electric circuit including an auxiliary electrode so placed as to receive an unobstructed stream of said secondary electrons.

'14. A rectifying tube including a cathode the primary electrons upon said first men tioned anode, and a control electrode for said primary electrons, said control electrode being located out of the path of the stream of said primary electrons.

15. A rectifying tube including a cathode adapted to emit primary electrons, an anode disposed in the. path of said electrons, a second anode adapted to receive the secondary electrons produced by the impinging of the primary electrons upon said first mentioned anode, a control electrode for said primary electrons, andmagnetic means for causing said primary velectrons to impinge upon said first mentioned anode against the action of the electric field of said control electrode.

In testimony whereof, I have hereunto subscribed by name this 2nd day of April, 1919.

JosEPH SLEPIANL 

